一种新型涡轮叶栅非轴对称端壁造型的数值研究

为探讨非轴对称端壁造型降低涡轮叶栅二次流损失的有效性，构建基于高压涡轮直列叶栅的非轴对称端壁气动优化设计方法，并用NUMECA／FineTurbo模块对优化后的结果和原涡轮叶栅分别进行流场计算。结果表明：非轴对称端壁造型使叶栅通道的总压损失系数面降低了2．84％；改变了通道内的叶片载荷分布，形成了叶型的载荷后置；改善了流场内的流动结构，使气流的流动变得更加通畅；延迟了通道涡的过早形成，减小了通道涡的强度和尺度。因此，非轴对称端壁造型可以有效地降低涡轮叶栅通道内的二次流损失。

Numerical Investigation of a Novel Non-axisymmetric End-wall Contouring for Turbine Cascade

Aiming for investigating the effectiveness of using non-axisymmetric end wall contouring to reduce secondary flow losses in turbine cascade. Hence, concerning a high pressure linear turbine cascade, a system is established to search for the optimum profiled non-axisymmetric end wall. Hereafter, with respect to the con toured end-wall and baseline cascade, detailed numerical simulations are conducted on the turbine cascade flow field. Numerical results show that comparing the contoured end wall to the baseline cascade, the mass averaged total pressure loss is decreased by 2.84%, and the blade loadings in the blade channel are modified, further more, the modification of flow structures enhances flow performance, and thus the formation of the passage vortex is delayed to a large degree and the scale and intensity of the passage vortex is enormously decreased. Hence non-axisymmetric end-wall contouring is proved to be effective in reducing secondary flow losses in tur- bine cascade.